In the construction of patio door assemblies having one swinging door panel and one fixed door panel, it is common to form the jamb and head or members of wood and attaching the jamb members to an extruded plastic or aluminum sill member. A vertical astragal member is spaced between the jamb members and is also commonly formed of wood as are the rectangular frames for the fixed and swinging door panels. It is also common to use three or four butt hinges to mount the swinging door panel on either one of the jamb members or on the astragal member. The main patio door frame and each of the frames for the door panels have been constructed with sections of extruded plastics material such as a rigid polyvinylchloride (PVC). One of the jamb members or the astragal member and the adjacent extruded section of the swinging door frame are then notched or mortised for receiving a set of butt hinges.
The problems associated with previously produced patio door assemblies using extruded vinyl frame sections include the problems of sagging and warping of the main frame and/or the frame for the swinging door panel due to distortion of the different extrusions or profiles especially when the extrusions are notched for attaching the butt hinges. With any such patio door assembly using extruded rigid plastics or vinyl sections, it is highly desirable for the sections forming the main door frame and the sections forming the frame of each of the door panels to have a uniform profile or cross-sectional configuration so that the sections may be joined together with welded mitered corners to provide a high strength frame. The extruded sections and components should also be designed and assembled to eliminate the use of internal metal reinforcing members and to provide for substantial rigidity without distortion over an extended period of time.